I had a similar problem with a Bosch Classixx. The internal 'plumbing' was silted up with grease and detergent, which prevented a float from descending in its chamber to press the microswitch that controls the pump.
I searched online until I found a (spare parts) diagram of the machine, which helped me to dismantle the outer case.
The float chamber (on the left hand side of the machine) was easily removed and dismantled (snap together plastic parts) and I cleaned it using hot water. 100% fix, no cost.
Stonker, August 2010